In the decades since the Cuban revolutions the country's medical doctors famously served on many semi-official missions abroad. For instance, it has been reported that Venezuela under Hugo Chavez provided cheap oil to the island, while the Castros sent their doctors (as well as sports instructors) in return. Cuban physicians effectively became an important export article.
Was this special national ability the result of deliberate planning or tradition on the island (an earlier versions of some emerging countries' current efforts on providing offshore medical services or an upscale version of nurses from the Philippines, perhaps) or did it just emerge as a by-product of a socialist state's common tendency to put relatively much effort on basic services such as medical care? The Wikipedia article on Cuban medical internationalism goes into many details, but is relatively light on the phenomenon's early history and ultimate causes.
So I am looking for sources more reliable than Michael Moore and I would be esp. interested in any memoirs that may exist from Cuban doctors having served in African countries during the Cold War period: Che Guevara, M.D. does not count :)